1. Field of the Invention
The present invention generally relates to measuring instruments and, more particularly, to measuring instruments for gemstones which permit measurement along multiple axes without manual intervention.
2. Prior Art
Gemstones such as diamonds, emeralds and rubies are classified according to weight and shape. The weight of a gemstone may be determined by measuring one to three dimensions of the gemstone with a set of calipers and then referring to appropriate tables for the corresponding weight. The measurement of a gemstone was classically taken through the use of mechanical calipers which employ either spring-loaded caliper jaws or a thumbwheel control to place the caliper jaws adjacent the respective surfaces of the gemstone.
Manufacturers of jewelry incorporating gemstones have long recognized the necessity to be able to accurately determine the physical size and therefore the value of gemstones. This necessity is created by the frequent need to determine the weight of the gemstone or to properly measure dimensions for specific designs. In conventional instruments used to measure linear dimensions, a vernier scale or dial indicator is generally used. However, this category of instruments is inadequate because of the probability of misreading the typical analog display due to reading errors and human error in that the user is required to interpret mechanically measured dimensions. Such conventional measuring instruments are also inadequate in that the primary scale of measurement is based upon a fixed calibration of the instrument.
The instruments disclosed in the prior art which are employed for measuring the physical dimensions of gemstones exhibit additional inadequacies. Gemstones must be measured along multiple of axes in order to provide the information necessary to determine actual size and value. Where these measurements are attempted by manually repositioning the gemstone, this step will inject the added problems of misalignment of the gemstone and the unnecessary expenditure of time. These problems are not in any way addressed by the conventional measuring instruments disclosed in the prior art.
The measuring instruments disclosed in the prior art have progressed through the use of digital displays. The devices are generally referred to as caliper apparatus. A caliper apparatus disclosed by the prior art utilizes a magnescale in which magnetic calibrations are provided on a magnetic tape and a signal produced due to the movement of the scale relative to the magnetic tape. This is sensed to measure dimension. Another caliper device employs a linear encoder in which light is directed toward an optical measuring device in which light is reflected from a first member and received by a second member of the device. Reflected light is sensed to measure dimension. In yet another caliper device, a rotary encoder is employed in which a rotatable first member is rotated relative to a rotatable second member and bright and dark patterns of light are sensed to measure dimension. In all these cases, the problem related to the manual interpretation of a measurement is replaced by a digital display which eliminates reading errors and human error. However, these devices continue to be inadequate for the measurement of gemstones since the measurement of the gemstone along multiple axes has required manual intervention by the user.
Another device disclosed by the prior art is one which is hand held, but uses spring-loaded caliper jaws to measure the dimensions of multiple axes of the gemstone. Although this device also provides means for automatically calculating the gemstone weight, it suffers from the same inadequacies as other devices described in the prior art. To measure multiple axes of a gemstone, these devices all require the manual manipulation of the gemstone to permit measurement of the relevant dimensions thereof.
The present invention substantially resolves those inadequacies inherent in those devices disclosed in the prior art. The present invention employs known means for determining the dimensions of a selected axis of a gemstone. The member used for measurement can be mechanically adjusted caliper jaws which provide for an analog or digital display, or even those which utilize magnetic or optical measuring devices. The improvement provided by the present invention relates to the ability to measure multiple axes of the gemstone without manual contact between the user and the gemstone. A rotatable platform is provided upon which the gemstone is mounted. The axis of the rotatable platform is co-extensive with an edge of the gemstone. Once the gemstone is mounted on the rotatable platform, the measurement means are placed adjacent the surfaces of the gemstone through which the measured axis extends. To obtain measurements for other axes of the gemstone, the platform is rotated to a selected axis of the gemstone and the measurement repeated. As a result, all axes of the gemstone relevant to determining the commercial weight thereof can be measured without physical interaction between the user and the gemstone.
The present invention comprises an improved measurement apparatus for measuring the dimensions of small objects in general, and gemstones in particular. The novel structural features of the present invention can be employed with any number of conventional measurement apparatus. For the purpose of example only, and without limiting the scope of the invention, the present invention employs a measurement apparatus pursuant to which selected dimensions are measured between a pair of measurement flanges. One of the measurement flanges is fixed, the second measurement flange being moveable to receive the gemstone irrespective of size. A rotatable platform is disposed adjacent the fixed measurement flange, the axis of the rotatable platform adapted to be perpendicular to the dimension of the gemstone being measured. In operation, the gemstone is placed on the rotatable platform, the axis of the gemstone to be measured to be aligned with the axis of the aligned measurement flanges. A plurality of dimensions of the gemstone may be measured merely by altering the position of the rotatable platform about its axis. The measurement of all relevant dimensions of the gemstone may be performed without any manual contact between the user and the gemstone.
It is therefore an object of the present invention to provide an improved gemstone measurement apparatus.
It is another object of the present invention to provide an improved gemstone measurement apparatus which permits measurement along multiple axes of the gemstone through the use of a rotatable support platform for the gemstone.
It is still yet another object of the present invention to provide an improved gemstone measurement apparatus which permits multiple measurements of the gemstone in the absence of any movement of the gemstone relative to the rotatable support platform.
It is still yet another object of the present invention to provide an improved gemstone measurement apparatus which is simple and inexpensive to fabricate.
The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objectives and advantages thereof, will be better understood from the following description considered in connection with the accompanying drawing in which a presently preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawing is for the purpose of illustration and description only, and is not intended as a definition of the limits of the invention.